Pneumatic vehicle dynamics control systems and ride control systems, such as brake systems and suspension systems, for heavy vehicles have been known and used for many years. Pressurized air has been used not only as the force to actuate components of such systems but also as the medium to convey control information to various system components.
More recently, control information has been transmitted to heavy vehicle dynamics control and ride control system components by electrical signals. Typically, a single task processor or electrical switch provides control information to a single type of component. The control information is generated according to a scheme in response to sensor input of vehicle performance factors. Each system component includes an electrical actuator for receiving and interpreting the control signal to operate the pneumatic component.
A disadvantage of known systems is their complexity in terms of design, assembly, maintenance, and refurbishment. Factors increasing complexity include a high number of individual components, using pressurized air for both control information and application force, and conflicts between control strategies. These disadvantages are exacerbated by the proliferation of different types of control strategies. For example, inherent conflicts existing between antilock braking, traction, manual inputs/overrides, and other vehicle dynamics schemes can lead to “lost” or cycling braking systems creating a safety hazard.